Devices for channel selection are well known in the art from current Internet protocol television systems, further referred to as IPTV systems, wherein a user is able to manually select a channel from a plurality of IPTV channels. The classical IPTV solution is shown in FIG. 1. The IPTV server infrastructure is basically composed of a multicast part and a fast channel change part. Both parts can be collocated or not. The IPTV client issues a Channel Change Request (CCR) for channel x and receives the channel data (CD) a short time later. The channel selection may be dealt with by just sequentially zapping through each of the channels till a channel is found with content that is interesting for the user. In closed IPTV systems, viewer satisfaction levels are decreasing. As the number of available channels grows, viewers end up in endless zapping loops, looking for better content and still missing the interesting content. On system level the high zapping rates lead to higher bandwidth (BW) requirements for the network and additional BW and processing power in “fast channel change” devices and operations.
At the same time the distribution of video streams is rapidly evolving from multicast to unicast. Content is more and more consumed on demand or delayed in time. Instead of having only a few video flows, consumed by many people and efficiently distributed using multicast techniques, operators are more and more facing video streams that serve only one household or even one single user. This puts an enormous burden on the network in terms of BW requirements.
An improvement in terms of bandwidth requirements was proposed in the reduction of the number of zaps probably obtainable through the use of channel-mosaic that provides a quick overview by combining a number of individual channels with corresponding content into one picture. Using the mosaic, the user can decide with less zaps in comparison to the sequential zapping through the plurality of channels, which channel has his preference. However, the use of channel-mosaic still has disadvantages. A single screen of the mosaic may only contain about 25 channels which renders the solution not scalable with 200 or more IPTV channels. Moreover, its use is not widely adopted under TV-spectators because it offers only a limited added value for the user. The user must stop watching while searching for a better channel. Hence, only a small amount of unnecessary zaps can be prevented through the provisioning of a channel mosaic. The reduction of the zapping-load on the network components is still minor.
Another way to deal with the increasing BW requirements caused by unicast streaming, is adding caching devices and replica servers to the network. These devices replicate and store the content closer to the customer in an attempt to reduce the BW requirements in the network. These techniques all look for a new optimum between the cost of BW and the cost of storage. Since storage cost is decreasing more rapidly than BW cost, this is feasible.
To improve viewer satisfaction and to reduce the need for zap-bound resources, IPTV components such as set top boxes or access nodes can be equipped with a “learning device”, with the intention to avoid unnecessary zaps. This solution was proposed in European patent application EP 07291510. This document discloses an Internet protocol TV channel selection device wherein the number of zaps, required for finding content that is interesting for the user, is reduced significantly by using at least one user-related selection criterion (i.e. a user preference) together the information on the various channels extracted from the electronic program guide (EPG). In other words, based on a user-profile and the meta-information on the various channels, the device becomes a personal zapping assistant. In this way the viewer can be triggered when (more) interesting content is currently being broadcasted or becomes available in the Video-on-Demand (VoD) database. To get the preferred content to the user, the IPTV system can create one or more artificial, personal channels, composed of already available broadcast and VoD content. Further, based on the viewer's profile, advertisings can be made more personal and effective because they are based on the profile.
Nevertheless, purely profile based systems have a number of drawbacks. First, they are not able to react on massive channel-zapping of other viewers. The purely profile-based system is unable to trigger the viewer in case there are massive zapping movements in the network towards content that is not 100 matching the user's interest. Example: when the normal programming is interrupted for a news flash on some disaster that has happened, a massive zap movement may take place. People may be calling friends and family to watch. From all channels, viewers are zapping to a same channel. If a pure profile based viewer did not specify news as a preference, he would miss this broadcasting. Secondly, also social aspects are missing. Some examples are                It may be that in general, a viewer is not interested in news (i.e; news is not in his profile), except when something is broadcasted that has a link to his life, his family, his friends or the neighbourhood.        If 70% of the family zapped to a travel program, this program is maybe filmed at a location that you actually visited with your family. You probably want to watch the program, even if travel-programs are not your favourite type of content.        If a large percentage of your friends and colleagues zap to a certain movie that is being broadcasted, this film might be interesting to watch, even if the director and actors are missing in your personal profile.A third disadvantage of purely profile based systems is its static behaviour: a profile system tends to lock the viewer in a limited set of predefined types of content. In that way, the system actually prevents users to discover new, but related types of content. Further there is also the bandwidth problem, as the profile-based system does not offer any solution for the increasing number of unicast flows in the network.        
Consequently, there is a strong need for improvement in the field of channel selection devices for IPTV systems.
Aims Of The Invention
The present invention aims to provide an improved device for to channel selection in an IPTV system wherein the above-mentioned problems are avoided or overcome.